High APOBEC1 Complementation Factor Expression Positively Modulates the Proliferation, Invasion, and Migration of Endometrial Cancer Cells Through Regulating P53/P21 Signaling Pathway

Genetic alteration of mRNA editing enzyme APOBEC3B in the pathogenesis of ovarian endometriosis

RESEARCH QUESTION

What are the specific genetic alterations and associated network in endometriotic cells responsible for the disease pathogenesis?

DESIGN

Case control experimental study involving 45 women with endometriosis who underwent laparoscopic surgery (case) and 45 normal samples from women undergoing total abdominal hysterectomy (control). The endometrial samples were subjected to whole exome sequencing (WES) of endometriotic tissue and copy number variation analysis. Validation of gene hits were obtained from WES using polymerase chain reaction techniques, immunological techniques, in-silico tools and transgenic cell line models.

RESULTS

Germline heterozygous deletion of mRNA editing enzyme subunit APOBEC3B was identified in about 96% of endometriosis samples. The presence of germline deletion was confirmed with blood, endometrium and normal ovary samples obtained from the same patient. APOBEC3B deletions resulted in a hybrid protein that activates A1CF. APOBEC3B deletion can be a major cause of changes in the endometriotic microenvironment, and contributes to the pathogenesis and manifestation of the disease. The effect of APOBEC3B deletion was proved by in-vitro experiments in a cell line model, which displayed endometriosis-like characteristics. APOBEC3B germline deletion plays a major role in the pathogenesis of endometriosis, which is evident by the activation of A1CF, an increase in epithelial to mesenchymal transition, cellular proliferation, inflammation markers and a decrease in apoptosis markers.

CONCLUSION

The deleterious effects caused by APOBEC3B deletion in endometriosis were identified and confirmed. These results might provide a base for identifying the complete pathogenetic mechanism of endometriosis, thereby moving a step closer to better diagnosis and treatment options.

APOBEC-1 Complementation Factor: From RNA Binding to Cancer

BACKGROUND

APOBEC-1 complementation factor (A1CF) and Apolipoprotein B mRNA editing enzyme, catalytic polypeptide-1 (APOBEC-1) constitute the minimal proteins necessary for the editing of apolipoprotein B (apoB) mRNA in vitro. Unlike APOBEC-1 and apoB mRNA, the ubiquitous expression of A1CF in human tissues suggests its unique biological significance, with various factors such as protein kinase C, thyroid hormones, and insulin regulating the activity and expression of A1CF. Nevertheless, few studies have provided an overview of this topic.

OBJECTIVE

We conducted a literature review to describe the molecular mechanisms of A1CF and its relevance to human diseases.

METHOD

In the PubMed database, we used the keywords 'A1CF' and 'APOBEC-1 complementation factor' to collect peer-reviewed articles published in English from 2000 to 2023. Two authors independently reviewed the articles and reached the consensus.

RESULT

After reviewing 127 articles, a total of 61 articles that met the inclusion criteria were included in the present review. Studies revealed that A1CF is involved in epigenetic regulation of reproductive cells affecting embryonic development, and that it is closely associated with the occurrence of gout due to its editing properties on apoB. A1CF can also affect the process of epithelial-mesenchymal transition in renal tubular epithelial cells and promote liver regeneration by controlling the stability of IL-6 mRNA, but no influence on cardiac function was found. Furthermore, increasing evidence suggests that A1CF may promote the occurrence and development of breast cancer, lung cancer, renal cell carcinoma, hepatocellular carcinoma, endometrial cancer, and glioma.

CONCLUSION

This review clarifies the association between A1CF and other complementary factors and their impact on the development of human diseases, aiming to provide guidance for further research on A1CF, which can help treat human diseases and promote health.

Characterization of molecular subtypes based on chromatin regulators and identification of the role of NPAS2 in lung adenocarcinoma

BACKGROUND

Chromatin regulators (CRs) are critical epigenetic modifiers and have been reported to play critical roles during the progression of various tumors, but their role in lung adenocarcinoma (LUAD) has not been comprehensively studied.

METHODS

Differential expression and univariate Cox regression analyses were conducted to identify the prognostic CRs. Consensus clustering was applied to classify the subtypes of LUAD based on prognostic CRs. LASSO-multivariate Cox regression method was used for construction of a prognostic signature and development of chromatin regulator-related gene index (CRGI). The capacity of CRGI to distinguish survival was evaluated via Kaplan-Meier method in multiple datasets. Relationship between CRGI and tumor microenvironment (TME) was evaluated. Additionally, clinical variables and CRGI were incorporated to create a nomogram. The role of the prognostic gene NPAS2 in LUAD was elucidated via clinical samples validation and a series of in vitro and in vivo experiments.

RESULTS

Two subtypes of LUAD were classified based on 46 prognostic CRs via consensus clustering which had significantly different survival and TME. A prognostic signature consisting of six CRs (MOCS, PBK, CBX3, A1CF, NPAS2, and CTCFL) was developed and proved to be an effective survival predictor in multiple independent datasets. The prognostic signature was also demonstrated to be an indicator of TME and sensitivity to immunotherapy and chemotherapy. The nomogram was suggested to be a simple tool that can predict survival accurately. Clinical samples show that NPAS2 is highly expressed in LUAD tissues, and in vitro and in vivo experiments demonstrated that inhibition of NPAS2 impeded malignant progression of LUAD cells.

CONCLUSIONS

Our study comprehensively unveiled the functions of CRs in LUAD, developed a classifier to predict survival and response to treatments, and suggested that NPAS2 promoted LUAD progression for the first time.

Computational approaches for discovering significant microRNAs, microRNA-mRNA regulatory pathways, and therapeutic protein targets in endometrial cancer

Endometrial cancer (EC) is a urogenital cancer affecting millions of post-menopausal women, globally. This study aims to identify key miRNAs, target genes, and drug targets associated with EC metastasis. The global miRNA and mRNA expression datasets of endometrial tissue biopsies (24 tumors +3 healthy tissues for mRNA and 18 tumor +4 healthy tissues for miRNAs), were extensively analyzed by mapping of DEGs, DEMi, biological pathway enrichment, miRNA-mRNA networking, drug target identification, and survival curve output for differentially expressed genes. Our results reveal the dysregulated expression of 26 miRNAs and their 66 target genes involved in focal adhesions, p53 signaling pathway, ECM-receptor interaction, Hedgehog signaling pathway, fat digestion and absorption, glioma as well as retinol metabolism involved in cell growth, migration, and proliferation of endometrial cancer cells. The subsequent miRNA-mRNA network and expression status analysis have narrowed down to 2 hub miRNAs (hsa-mir-200a, hsa-mir-429) and 6 hub genes (PTCH1, FOSB, PDGFRA, CCND2, ABL1, ALDH1A1). Further investigations with different systems biology methods have prioritized ALDH1A1, ABL1 and CCND2 as potential genes involved in endometrial cancer metastasis owing to their high mutation load and expression status. Interestingly, overexpression of PTCH1, ABL1 and FOSB genes are reported to be associated with a low survival rate among cancer patients. The upregulated hsa-mir-200a-b is associated with the decreased expression of the PTCH1, CCND2, PDGFRA, FOSB and ABL1 genes in endometrial cancer tissue while hsa-mir-429 is correlated with the decreased expression of the ALDH1A1 gene, besides some antibodies, PROTACs and inhibitory molecules. In conclusion, this study identified key miRNAs (hsa-mir-200a, hsa-mir-429) and target genes ALDH1A1, ABL1 and CCND2 as potential biomarkers for metastatic endometrial cancers from large-scale gene expression data using systems biology approaches.

Role of HIF-1α/ERRα in Enhancing Cancer Cell Metabolism and Promoting Resistance of Endometrial Cancer Cells to Pyroptosis

Oxygen is critical to energy metabolism, and tumors are often characterized by a hypoxic microenvironment. Owing to the high metabolic energy demand of malignant tumor cells, their survival is promoted by metabolic reprogramming in the hypoxic microenvironment, which can confer tumor cell resistance to pyroptosis. Pyroptosis resistance can inhibit anti-tumor immunity and promote the development of malignant tumors. Hypoxia inducible factor-1α (HIF-1α) is a key regulator of metabolic reprogramming in tumor cells, and estrogen-related receptor α (ERRα) plays a key role in regulating cellular energy metabolism. Therefore, the close interaction between HIF-1α and ERRα influences the metabolic and functional changes in cancer cells. In this review, we summarize the reprogramming of tumor metabolism involving HIF-1α/ERRα. We review our understanding of the role of HIF-1α/ERRα in promoting tumor growth adaptation and pyroptosis resistance, emphasize its key role in energy homeostasis, and explore the regulation of HIF-1α/ERRα in preventing and/or treating endometrial carcinoma patients. This review provides a new perspective for the study of the molecular mechanisms of metabolic changes in tumor progression.

Research Progress of PCNA in Reproductive System Diseases

Reproductive system diseases have become a public health problem that endangers human physical and mental health. The causes of reproductive diseases are complex and diverse. From a biological point of view, abnormal cell proliferation may affect important physiological functions of reproductive organs and cause various gynecological or andrological diseases. Proliferating cell nuclear antigen (PCNA) is the most commonly used indicator for detecting cell proliferation activity. The up- or downregulation of its expression is of great significance in reproductive system diseases. This review summarizes the significance of the latest research on PCNA expression in reproductive system diseases.

APOBEC1 complementation factor facilitates cell migration by promoting nucleus translocation of SMAD3 in renal cell carcinoma cells

Metastasis is inevitable in about 30% of patients with primary renal cell carcinoma after nephrectomy treatment. APOBEC1 complementation factor (A1CF), an RNA binding protein, participates in tumor progressions such as growth, apoptosis, differentiation, and invasion. Here, we explored biological functions of A1CF and provided a new insight into renal cell carcinoma metastasis. Wound healing assay was conducted to detect migration in A1CF overexpression and knockdown stable cell lines. Quantitative PCR and western blot assays were utilized to test transcriptional and translation levels of A1CF and SMAD3 in A1CF overexpression and knockdown renal carcinoma cells. Nuclear and cytoplasmic protein separation assays were conducted to evaluate the subcellular distribution of A1CF and SMAD3. Immunoprecipitation assay was conducted to detect the interaction between A1CF and SMAD3. Our study demonstrated A1CF overexpression facilitated cell migration in renal carcinoma cells. A1CF deficiency downregulated expression of SMAD3, Snail1, and N-cadherin. In addition, A1CF promoted nucleus translocation of SMAD3 and interacted with SMAD3. SMAD3 knockdown attenuated cell migration induced by A1CF overexpression. Our study suggested A1CF facilitated cell migration by promoting nucleus translocation of SMAD3 in renal cell carcinoma cells.